[Brain-derived neurotrophic factor: from nerve growth factor to modulator of brain plasticity in cognitive processes and psychiatric diseases].

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family and plays an important role in neuronal survival and plasticity in the CNS. The proform of BDNF (pro-BDNF) is secreted and cleaved extracellularly by the serine protease plasmin to mature BDNF, which potentiates synaptic plasticity and long-term potentiation. Recent findings in animal models suggest an involvement of BDNF and its genetic functional single nucleotide polymorphism in the pathogenesis of different psychiatric diseases including depression, mania, schizophrenia, eating disorders, dementia, and Huntington's disease. In the brain and serum, BDNF is modulated by different factors. It is downregulated by stress and upregulated by learning processes, several antidepressive treatments, physical activity, and dietary restriction. Measurement of BDNF serum concentrations may be of diagnostic value. Additionally, the influence of different strategies for BDNF allocation seems to be relevant for the treatment and prevention of the above psychiatric disorders.